Linux 5.7 compat: blk_alloc_queue()

Commit https://github.com/torvalds/linux/commit/3d745ea5 simplified
the blk_alloc_queue() interface by updating it to take the request
queue as an argument.  Add a wrapper function which accepts the new
arguments and internally uses the available interfaces.

Other minor changes include increasing the Linux-Maximum to 5.6 now
that 5.6 has been released.  It was not bumped to 5.7 because this
release has not yet been finalized and is still subject to change.

Added local 'struct zvol_state_os *zso' variable to zvol_alloc.

Reviewed-by: George Melikov <[email protected]>
Reviewed-by: Tony Hutter <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #10181 
Closes #10187 

1 files changed, 48 insertions, 19 deletions

diff --git a/config/kernel-make-request-fn.m4 b/config/kernel-make-request-fn.m4
index 5183176f5..609926c1b 100644
--- a/config/kernel-make-request-fn.m4
+++ b/config/kernel-make-request-fn.m4
@@ -17,38 +17,67 @@ AC_DEFUN([ZFS_AC_KERNEL_SRC_MAKE_REQUEST_FN], [
 	],[
 		blk_queue_make_request(NULL, &make_request);
 	])
+
+	ZFS_LINUX_TEST_SRC([blk_alloc_queue_request_fn], [
+		#include <linux/blkdev.h>
+		blk_qc_t make_request(struct request_queue *q,
+		    struct bio *bio) { return (BLK_QC_T_NONE); }
+	],[
+		struct request_queue *q __attribute__ ((unused));
+		q = blk_alloc_queue(make_request, NUMA_NO_NODE);
+	])
 ])
 
 AC_DEFUN([ZFS_AC_KERNEL_MAKE_REQUEST_FN], [
 	dnl #
-	dnl # Linux 3.2 API Change
-	dnl # make_request_fn returns void.
+	dnl # Linux 5.7 API Change
+	dnl # blk_alloc_queue() expects request function.
 	dnl #
-	AC_MSG_CHECKING([whether make_request_fn() returns void])
-	ZFS_LINUX_TEST_RESULT([make_request_fn_void], [
+	AC_MSG_CHECKING([whether blk_alloc_queue() expects request function])
+	ZFS_LINUX_TEST_RESULT([blk_alloc_queue_request_fn], [
 		AC_MSG_RESULT(yes)
-		AC_DEFINE(MAKE_REQUEST_FN_RET, void,
+
+		dnl # Checked as part of the blk_alloc_queue_request_fn test
+		AC_MSG_CHECKING([whether make_request_fn() returns blk_qc_t])
+		AC_MSG_RESULT(yes)
+
+		AC_DEFINE(HAVE_BLK_ALLOC_QUEUE_REQUEST_FN, 1,
+		    [blk_alloc_queue() expects request function])
+		AC_DEFINE(MAKE_REQUEST_FN_RET, blk_qc_t,
 		    [make_request_fn() return type])
-		AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_VOID, 1,
-		    [Noting that make_request_fn() returns void])
+		AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_QC, 1,
+		    [Noting that make_request_fn() returns blk_qc_t])
 	],[
-		AC_MSG_RESULT(no)
-
 		dnl #
-		dnl # Linux 4.4 API Change
-		dnl # make_request_fn returns blk_qc_t.
+		dnl # Linux 3.2 API Change
+		dnl # make_request_fn returns void.
 		dnl #
-		AC_MSG_CHECKING(
-		    [whether make_request_fn() returns blk_qc_t])
-		ZFS_LINUX_TEST_RESULT([make_request_fn_blk_qc_t], [
+		AC_MSG_CHECKING([whether make_request_fn() returns void])
+		ZFS_LINUX_TEST_RESULT([make_request_fn_void], [
 			AC_MSG_RESULT(yes)
-			AC_DEFINE(MAKE_REQUEST_FN_RET, blk_qc_t,
+			AC_DEFINE(MAKE_REQUEST_FN_RET, void,
 			    [make_request_fn() return type])
-			AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_QC, 1,
-			    [Noting that make_request_fn() ]
-			    [returns blk_qc_t])
+			AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_VOID, 1,
+			    [Noting that make_request_fn() returns void])
 		],[
-			ZFS_LINUX_TEST_ERROR([make_request_fn])
+			AC_MSG_RESULT(no)
+
+			dnl #
+			dnl # Linux 4.4 API Change
+			dnl # make_request_fn returns blk_qc_t.
+			dnl #
+			AC_MSG_CHECKING(
+			    [whether make_request_fn() returns blk_qc_t])
+			ZFS_LINUX_TEST_RESULT([make_request_fn_blk_qc_t], [
+				AC_MSG_RESULT(yes)
+				AC_DEFINE(MAKE_REQUEST_FN_RET, blk_qc_t,
+				    [make_request_fn() return type])
+				AC_DEFINE(HAVE_MAKE_REQUEST_FN_RET_QC, 1,
+				    [Noting that make_request_fn() ]
+				    [returns blk_qc_t])
+			],[
+				ZFS_LINUX_TEST_ERROR([make_request_fn])
+			])
 		])
 	])
 ])